The following description relates to a laminated nozzle assembly having one or more thick plates.
A laminated nozzle assembly may be used to discharge a hot melt adhesive onto a substrate. The substrate may be, for example, a layer of material, such as a nonwoven fabric, or a strand of material, such as an elastic strand to be applied on an article, such as a disposable hygiene product. The laminated nozzle assembly may include one or more first orifices for discharging the hot melt adhesive and one or more second orifices configured to discharge air. The discharged air causes the discharged hot melt adhesive to oscillate or vacillate during application to the substrate.
FIG. 1 shows a partial exploded view of a conventional laminated nozzle assembly 10. Referring to FIG. 1, a conventional laminated nozzle assembly 10 includes a plurality of plates having internal conduits formed therein allowing flow of the hot melt adhesive and air therethrough. FIG. 2 is a plan view of the individual plates forming the conventional laminated nozzle assembly 10. Referring to FIGS. 1 and 2, the conventional laminated nozzle assembly may include eleven plates 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32 secured between a first end plate 34 and a second end plate 36. A first internal conduit 38 may be formed through a plurality of the plates for delivering the hot melt adhesive to a first orifice 40. The first conduit 38 is formed by a plurality of aligned openings in the plates. A second internal conduit 42 may also be formed through a plurality of the plates for delivering the air to a second orifice 44. The second conduit 42 is formed by a plurality of aligned openings in the plates.
However, in the conventional laminated nozzle assembly 10, the fluid may collect in various portions of the conduits 38, 42, and in the case of the hot melt adhesive, may lead to plugging of the first conduit. Fluid collection may be the result of narrow or small flow paths, indirect flow paths that cause the velocity of a fluid to be reduced, or excess contact with the sidewalls of a conduit (i.e., the portions of the plates surrounding the openings forming the conduits).
Moreover, when the chemistry and manufacturing of the discharged material (e.g., the adhesive) is not well controlled, contaminants may be present in the material and charring may occur at what are otherwise normal operating temperatures. The existence of contaminants, char products and residue can further exaggerate the plugging of the conduits.
Accordingly, it is desirable to provide a laminated nozzle assembly having an internal conduit or conduits allowing for increased passageway size, higher fluid velocity, and more direct flow paths to the discharge orifices.